Using HIV to cure leukemia? Maybe. Immune boost is key

December 11, 2012
| by Shawn Le

On the surface, the idea of using HIV to treat leukemia might seem far-fetched, but researchers from the University of Pennsylvania were recently able to harness HIV's ability to infect white blood cells, developing what seems to be a cancer cure – or at least total remission – for a handful of patients. And they're not alone in using this increasingly promising approach.

The Pennsylvania team's HIV-based treatment, presented at the American Society of Hematology meeting and reported this week by the New York Times, is a new addition to the numerous treatments in development using T cells, a type of white-blood cell. Known as immunotherapeutics, these therapies use a patient's own immune system to fight disease.

HIV-infected T cells, shown here under high magnification, may become a powerful new cancer treatment. (Image credit: Comstock)

Such therapies are most often aimed at rebooting the body's immune system to overcome cancer cells' abilities to evade identification, attack and eradiation; the therapies also boost production of immune cells, further helping overwhelm the cancer.

The University of Pennsylvania's leukemia treatment gets a boost from HIV's ability to infect cells, which helps spread the treatment throughout the body.

In the case cited by the New York Times, researchers reprogrammed T cells from then-6-year-old Emma Whitehead using neutered HIV – its infection prowess untouched but its disease genes replaced with anti-cancer genes. When the cells were reinfused into Emma, the viral package infected the other T cells in Emma's body, creating a new army of leukemia-targeted T cells that destroyed her cancer.

Twelve patients, including Emma, were treated with the HIV immunotherapeutic, but not all patients experienced remission of their cancers. One patient experienced a cancer recurrence.

In fact, although Emma's results were positive, she did endure harrowing fevers and chills – and dangerous blood pressure drops – during treatment, prompted by her rebooted immune system. More research is needed to understand why treatment results varied.

City of Hope's own immunotherapy research has identified cancer-specific receptors that can be used to target treatment, discovered specific T cells that can track down cancer cells hiding in lymph nodes, and opened clinical trials using central memory T cells to potentially provide immunity against cancer relapse. Stephen J. Forman, M.D., chair of City of Hope's Department of Hematology & Hematopoietic Cell Transplantation and the Francis and Kathleen McNamara Distinguished Chair in Hematology and Hematopoietic Cell Transplantation, is leading clinical trials on these immunotherapeutics.

“Our use of central memory T cells as part of an autologous transplant is unique to our therapy and sets our approach apart from other T cell treatments in development,” said Forman in a previous interview. “Central memory T cells have the potential to establish a persistent, lifelong immunity to help prevent recurrence of lymphoma after [a bone marrow] transplant.”